Slate-picker.



No. 139.337. PATENTEB ses, 1903. G. W. (moss. SLATB PIGKER.

AEPLIQTIONTILBD EAB. 11, 1898.

I() NOBEL.

4: y .Izzi/enfer* 4UNITED Y STATES Patented September 29, 1903.

* PATENT OEEICE.

stmt-PICKER.

SPECIFICATION forming part of Letters Patent No. 739,837,

dated September 29, 1903.

Application filed March Il, 1898. Serial No. 673,545. (No model.)

To a/ZZ whom it may concern.-

Be it known that I, GEORGE W. CRoss, a citizen of the United States, residing at Carbondale, in the county of Lackawanna and State of Pennsylvania, have invented a certain new and useful Improvement in Slate- Iickers, of which the following is a specification.

My present invention relates to improvements in slate-pickers designed to separate slate from coal. As is well known, coal as it is presented to the screens contains particles of slate usually dat in form, whereas the coal itself fractures commonlyin other shapes. The object of the invention is to provide a durable mechanism cheap of manufacture for the efticient separation of these flat particles from the coal. Apparatus heretofore commonly employed for this purpose consists of cylindrical slate-pickers provided at intervals throughout its length with transverse elongated slots or openings for the escape of the particles of slate. Apparatus of this description, besides lacking the requisite degree of efficiency, cannot be manufacturedas cheaply as desirable, and in addition where made of sheet-steel lacks durability and where made of cast metal is of such excessive weight as to require stronger screen frameand shaft.

Stated more in detail than above it is the object of the present invention to provide a slate-picker which can be cheaply made, in that it can be stamped from sheetsteel,

which shall be durable, in that the wear due l to attrition will be equablyY distributed and which will carry on continuously and perfectly the operation of separating the coal from the slate.

In the drawings, Figure l is a transverse section of a revoluble screen or slate-picker made up of plates embodying my' improvement. Fig. 2 is a perspective view illustrating one of the slate-picker segments employed on the screen shown in Fig. l. Figs. 3 and 4; are detail sectional views illustrating modifications hereinafter to be referred to.

Referring to the drawings, in which-simi-Y lar letters denote corresponding parts, A designates the central shaft of Athe screen or slate-picker. Extending outwardly from this shaft are spider-arms a, the ends of which are commonly connected by spider-bands a', to which the segments are secured. The instru mentalities thus far described are those commonlyin use at the presenttime. Mounted upon the spider-bands in the present case is a series or round of the segments illustrated in Fig. 2. Referring particularly to said iigure it will be seen that the segment consists of an integral metallic sheet B, provided with margins h, having suitable bolt-holes by means of which the segment may be secured to the spider-bands of tho screen-frame and to adjoining segments. The surface of the segment B intermediate of its margins is provided with slots b', running longitudinally or in the direction of the length of the screen. As here shown, these slots or openings are formed by first slitting the plates longitudi-v done, since in the construction illustrated in Fig. 2 it is necessary only to bend the metallic webs. In the construction so shown each leaf is so canted as that one edge will lie aboveand the other below the working plane or the plane of the margins of the segment.

For some. uses it may be found desirable not to cant both edges of each leaf. Such structures are shown in Figs. 3 and 4c. In the former it will be seen that the forward edge only of each leaf is canted upwardly, While in the latter the rear edge only of each leaf is canted downwardly. In each of the latter cases approximately half (in Width) of the leaves b3 remain in the plane of the margins of the segment. .y

I attach importance in my invention as above described to the fact that while losing nothing in ease and economy of providing the longitudinal openings in the plates I am enabled to provide means for not only permit- IOC ting the escape of thev iat particles of slate, but for directing their escape by guiding them to the escape-orifices through which they pass without turning. In the construction shown in Fig. 1 it will be understood that the screen rotates in the direction of the arrow. If while so rotating the cylinder were supplied with a mass of composite coal and slate, the latter consisting ofthe characteristically I'lat particles, it is obvious that such particles would find their way to the interior surface of the plates and be guided to the openings through which they were designed to escape. This is equally true of the modifications illustrated and described and will be found quite possible in modifications of the invention other than those here shown and described.

The invention may be embodied equally well either in a segment, as above described, or in a contin-uous cylindrical jacket. The former varies greatly not only in dimensions, but also in the relation of breadth to thickness. Because of this fact I here observe that in referring-herein to a segment having longitudinal slots I have in mind the longitude of the screen as a whole rather than the form of the segment.

I claiml. As a new article of manufacture', a slatepicker plate or segment curved between its ends and provided with a series of elongated slots, the metal being canted between said slots and extending above and below the plane of said slots, substantially as set forth.

2. As a new article of manufacture, a slatepieker element curved between its ends and provided with a series of longitudinal elongated slots, the metal between said slots lying in a single plane and canted above and below the plane of said slots, substantially as set forth.

3. As a new article of manufacture, aslatepicker segment curved between its ends and provided with a series of elongated slots, the

\ metal between said slots lying in a single plane and canted above and below the plane of said slots, substantially as set forth.

4E. As a new article of manufacture, a slatepicker element provided with a series of longitudinal slots and having transverse slots extending on both sides of each longitudinal slot at both ends thereof, the metal being canted between said longitudinal' slots and extending above and below the plane of said slots, substantially as set forth.

5. As a new article. of manufacture, a slatepicker segment provided with a series of longitudinal slots and having transverse slots extending on both sides of each longitudinal slot at both ends thereof, the metal being canted between said longitudinal slots and eX- tending above and belowthe plane of said slots, substantially as set forth.

v6. As a new article of manufacture, a slatepicker plate provided with straight elongated parallel slots, the surface of the plate between each two slots lying in a single plane oblique to the plane of the margin of the plate, substantially as set forth. o

7. As a new article of manufacture, a slatepicker plate curved between its ends and provided with straight elongated parallel slots, the surface of the plate between each two slots lying in a single plane oblique to the plane of the margin of the plate, substantially as set forth.

8. Au improved slate-picker comprising a sheetmetalelement with louver-like slats and openings formed by a series of parallel straight slots or cuts extending nearly the entire width of the element, the metal between each two slots being canted out ofthe general plane or surface of the element, substantially as described.

9. An improved slate-picker comprising a sheet-metal segment with louver-like slats and openings formed by a series of parallel straight slots or cuts extending nearly the entire width of the segment, the whole of the metal between each two slots presenting a plane surface canted out of the general plane or surface of the segment, substantially as set forth.

This specification signed and witnessed this 25th day of February, 1898.

GEORGE W. CROSS. Witnesses: A

S. O. EDMoNDs, JN0. R. TAYLOR. 

